Drafting-tool



C. F. MINION. DRAFTING TOOL. APPLICATION FILED 001,4, 1920.

Patented Nov. 1, 1921.

Fig. 5

Snirefftor PATENT OFFICE.

CARL F. MINION, OF CINCINNATI, OHIO.

DRAFTING-TOOL.

Specification of Letters Patent.

Patented Nov. 1, 1921.

Application filed October 4, 1920. Serial No. 414,404.

T 0 all whom it may concern: 7

Be it known that I, CARL F. MINION, a, citizen of the United States, and a resident, of the city of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Drafting-Tools, of which the following is a 1 full, clear, and exact description, reference being had to the drawings, forming part of this specification.

This invention relates to drafting tools and is designed more especially to make possible greater accuracy and to avoid the need of much calculating in drafting work.

The object of this invention is to aflord a simple and inexpensive device of thischan acter, whereby any desired number of parallel lines or points between two or more lines or points may be accurately determined and easily drawn.

Io these ends the invention consists in the novel construction and arrangement of parts as will be hereinafter described and claimed.

In the drawings Figure 1 is a plan view of a drafting tool embodying the present invention.

Fig. 2 is a horizontal section taken on the line B-B shown in Fig. 1. Fig. 3 is a longitudinal section taken on the line AA in F ig. 1.

eferring to the drawings the numeral 1 designates a triangular board or base plate with a circular piece cut out at 2 in the cen; ter on the front face and a concentric circular piece of slightly larger diameter cut out at 3 on the reverse face so that the circular offset 23 shall hold in position the rotating plate 4 hereinafter described. This plate 4: is a round disk made of celluloid or other transparent material of a diameter and thickness which will fit snugly into the opening in the base plate designated between the numerals 23.

This plate 4 has two scales mounted across it diametrically designated by the numerals 5 and 6 and is held in position where it will be free to rotateby a strip 7 mounted between the scales which project over the surface of the base plate at the top and bot tom at 7, 7 The top 7' is the indicator point for a degree scale 10 on the base plate and the bottom 7 extends out across the slot 9 in the base plate where it can be conveniently held in any desired position by the thumb screw 8.

The scales 5 and 6 are graduated in 1 spectively or -in other suitable dimensions according to the size of the tool and at each graduation ahole is made of suitable size to admit the point of a pencil or other drawing stylus.

By the construction as. above explained this simple tool will be found useful for a variety of purposes in drafting work. As an example, in drawing a brick wall where two parallel lines are designated as the top and bottom of the wall and it is desired to draw in any number of parallel lines to represent the individual rows of bricks, the use of the tool renders unnecessary tedious calculating, measuring and marking the points on which the lines are to be drawn. If as a specific example the top and bottom of the wall are shown as two inches apart and it is desired to draw six parallel lines between them; the right hand scale with 12 as a multiple of six would be used, and by turning the scale so that the zero lies on the line representing the lower part of the wall, and 11 on the top line by tightening the thumb screw, squaring the bottom of the tool with a straight edge, inserting a pencil in the alternate numbers 2, 4;, 6, 8, 10, and 12 and sliding the tool along the straight edge, all six lines may be drawn in.

Thus in one simple operation the necessity is avoided of first calculating that the lines should be inch apart and then further calculating how to draw in lines inch apart when such a dimension is not found on any ordinary drafting ruler.

In drawing in risers for stairs it is quite simple to draw any number of stairs between fioors. Thus if it is desired to draw lines for 12 risers between two floor lines, the scale is slanted so that there are 12 graduations between the floor lines, the straight edge set and the pencil used in the holes as before. The motive force in moving the device to and fro is supplied by pressure on the pencil or stylus and as long as a cross line may be drawn as desired, with the device sliding to and fro with its edge in constant contact with the straight edge.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a drafting tool, a plate having a straight edge, an opening in the plate, a. linear member mounted in the plate so as to extend across said opening, said mounting being adapted to permita variety of angu lar positions of the linear member, the linear member having a series of apertures therein through which the point of a stylus may be vinserted, and means for locking the linear member in fixed position in the plate.

2. In a draftingtool, a plate-having a straight edge, an opening in the plate, a linear member mounted .in the plate so as to extend across said opening, said mounting linear member in fixed position in the plate, said -means compr1s1ng a clamp1ng screw on the linear member, and said plate having an arcuate slot in which thescrew engages.

:3. In a drafting tool, a plate having a straight edge, an opening in the plate, a ilinearmember mounted in the plate so as to described.

extend across said opening,said-mounting beingradapted to permit avariety of angular positions ofithe linear member, the linear member having a series of apertures therein -;t1 1rough which the point of a stylus may be inserted, and means for locking the linear member in fixed position in the plate, said linear member having a stralght'edge Where it extends across-the opening in the plate.

4. A draftsmans tool comprising a body portion, an annular member mounted on and revoluble on the body portion, a linear'mem- 'be! formed diametrically of the annular member and graduated as a scale, said linear member having perforations *formed therein at thegraduation po nt of the scalesuitable for the insertion of a stylus, the body portion having an arcuate slot and a clamp screw mounted .on the'annular member and engaging-1n said slot, as'and for thepurpose CARL r. MINION.

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